Molecular characterization of exons 6, 8 and 9 of ABCB4 gene in children with Progressive Familial Intrahepatic Cholestasis type 3

Aim of work: To estimate the frequency of mutations involving exons 6, 8 and 9 of Adenosine triphosphate-binding cassette, subfamily B, member 4 (ABCB4) gene among children with progressive intrahepatic cholestasis with high γ-GT activity (PFIC3).

Subjects and methods: Cross sectional study was conducted on 30 children with PFIC3. Genotyping was performed by sequencing analysis of exons 6, 8 and exon 9 of ABCB4 gene.

Results: Heterozygous synonymous polymorphic variant was detected in exon 6 (rs 1202283) and in exon 8 (rs 2109505). No mutations in studied exons were detected.

Conclusion: Exons 6, 8 and 9 mutations of ABCB4 gene are not common among Egyptian children with PFIC3.     

FIC1, a P-type ATPase linked to cholestatic liver disease,has homologues (ATP8B2 and ATP8B3) expressed throughout the body

ATP8B1/FIC1 is a member of the Type IV P-type ATPase family, which function as ATP dependent aminophospholipid translocases (APLT). We identified two familial intrahepatic cholestasis type 1 (FIC1) homologues, ATP8B2 and ATP8B3, with 53% and 45% amino acid identity, respectively. The expression profile for each gene was determined using a 73-tissue human RNA expression array. The subfamily of FIC1-like proteins is expressed in a wide range of tissues. Given that mutations in FIC1 result in liver disease, these proteins may have important roles in other organs in which they are candidates for genetic and acquired diseases.     

Epigenetic regulation of miR-124 by Hepatitis C Virus core protein promotes migration and invasion of intrahepatic cholangiocarcinoma cells by targeting SMYD3

Hepatitis C Virus core protein (HCVc) plays important roles in the development of intrahepatic cholangiocarcinoma (ICC). MicroRNAs (miRNAs) contribute to tumor progression by interacting with downstream target genes. However, the regulation and role of miRNAs in HCV-related intrahepatic cholangiocarcinoma (HCV-ICC) is poorly understood. In this study, we found that miR-124 was down-regulated in HCV-ICC and the induction of DNMT1 by HCVc mediated the suppression of miR-124. Over-expression of miR-124 suppressed cell migration and invasion in vitro, and reduced the protein levels of SMYD3 and downstream target genes (c-Myc and MMP9). Knockdown of SMYD3 inhibited cell migration and invasion resembling that of miR-124 over-expression. In conclusion, our studies indicate that low miR-124 levels mediated by HCVc via DNMT1 promote ICC cell migration and invasion by targeting SMYD3.     

七鳃鳗胆道闭锁过程中胆汁酸耐受机制研究进展

胆道闭锁(biliary atresia,BA)是一种罕见的婴幼儿肝胆疾病,其特征是纤维硬化性胆管病变,导致肝外胆管和肝内胆管阻塞或闭塞,胆汁不能向肠道排泄,胆汁酸对肝实质细胞造成严重损伤,最后导致肝硬化和肝衰竭危及生命.目前,胆道闭锁的发病机理尚不明确,临床上普遍采用"先葛西"、"后移植"的序贯性治疗方式.葛西手术(...     

Blocking intrahepatic deletion of activated CD8+ T cells by an altered peptide ligand

BACKGROUND: Activated CD8(+) T cells are retained by the healthy liver where the majority undergo apoptosis. The intrahepatic apoptosis of activated CD8(+) T cells is enhanced by the presence of SIINFEKL peptide. It is of great interest to identify strategies for maintaining intrahepatic T cell number and function in the presence of SIINFEKL peptides. AIM: Our aim was to test if low affinity peptides can block SIINFEKL peptide induced T cell deletion. METHODS: We used an in vivo model of intrahepatic CD8(+) T cell deletion with peptides of different affinities. RESULTS AND DISCUSSION: We show that the intrahepatic deletion of CD8(+) T cells by SIINFEKL peptide results in loss of in vivo cytotoxic T lymphocyte function. In contrast we show that a low affinity peptide (G4) does not result in intrahepatic deletion of CD8(+) T cells. High concentrations G4 peptide can however block intrahepatic deletion of activated CD8(+) T cells, and prevent loss of in vivo cytotoxicity due to SIINFEKL peptide. This is the first demonstration of blocking of SIINFEKL peptide induced CD8(+) T cell deletion in the liver, with enhancement of in vivo cytotoxicity.     

Molecular characterization of woodchuck interleukin 15 (wIL-15) and detection of its expression in liver samples of woodchucks infected with woodchuck hepatitis virus (WHV)

Interleukin 15 (IL-15) is a member of the four-helix bundle cytokine family and has T cell growth factor activity. IL-15 plays a unique role in both innate and adaptive immune cell homeostasis, particularly for the development of NK cells and CD8+memory cells. It may be useful for stimulation of specific immune responses in chronic viral infection such as hepatitis B virus infection. The woodchuck model is an informative animal model for studies on hepadnavirus infection and therapeutic interventions. Here, the complete coding sequence of woodchuck IL-15 (wIL-15) was cloned and sequenced. wIL-15 shows a high homology (>70%) to its counterparts of other mammalian species. His-tagged recombinant wIL-15 protein was expressed and purified and showed the ability to promote the proliferation of activated mouse splenocytes and woodchuck peripheral blood lymphocytes. Further, examination of mRNA amounts in liver samples of woodchucks by semi-quantitative RT-PCR showed a slightly increased expression of wIL-15 in woodchuck livers during chronic woodchuck hepatitis virus infection. This available information will provide a basis for further studies on the function of IL-15 in the context of acute and chronic hepadnavirus infection and its potential therapeutic use for chronic hepatitis B virus infection in the woodchuck model.     

妊娠期肝内胆汁淤积症合并妊娠期糖尿病的母儿结局分析

目的:探讨妊娠期肝内胆汁淤积症(ICP)合并妊娠期糖尿病(GDM)对母儿结局的影响。方法:选取2012年1月至2013年2月在我院住院分娩的13例ICP合并GDM孕妇为ICP+GDM组,将同期住院分娩的69例单纯ICP孕妇归为ICP组,对两组孕妇的母儿结局进行回顾性比较分析。结果:两组孕妇的子痫前期、胎膜早破、剖宫产、产后出血发生率比较,无明显差异(P0.05);ICP+GDM组孕妇围产儿Apgar小于7分、新生儿肺炎、早产发生率明显高于ICP组,差异有统计学意义(P均0.05);ICP+GDM组孕妇围产儿平均出生体重低于ICP组,差异有统计学意义(P0.05)。结论:妊娠期肝内胆汁淤积症合并妊娠期糖尿病将进一步加重围产儿不良结局,对于此类孕妇,应加强监护和管理,适时终止妊娠,以改善围产儿结局。     

Study of Hepatocytes Polyploidization Peculiarities in Cholestatic Liver of Adult Rats

According to the literature, different mechanisms and kinetics proceeding of regenerative growth has been established using the basic models of liver regeneration (after resection or chemically induced). Hence, in order to determine general regularities of the adaptive-compensatory processes in various pathological conditions, the processes taking place in the cholestatic liver of adult white rats during the first four days after common bile duct ligation have been studied. It has been shown that in cholestatic liver, compensatory-adaptive processes take place with different kinetics compared to those after resection. In particular, in response to the increased functional load caused by destructive processes during cholestasis, the liver, at an early stage, responds by simple division of high ploidy (binuclear tetraploid) cells and further provides their quantitative increase. The difference between the processes taking place in cholestatic and resected liver is more expressed on the third and fourth day after common bile duct ligation. In particular, 4c cells are still highest in cholestatic liver, while all ploidy cells are present in equal numbers in the regenerated liver after resection. This fact of compensatory growth characteristic for reparative regeneration was not detected in cholestatic liver at the mentioned date.     

Detection of Lipoprotein X (LpX): A challenge in patients with severe hypercholesterolaemia

BackgroundLipoprotein X (LpX) is an abnormal lipoprotein fraction, which can be detected in patients with severe hypercholesterolaemia and cholestatic liver disease. LpX is composed largely of phospholipid and free cholesterol, with small amounts of triglyceride, cholesteryl ester and protein. There are no widely available methods for direct measurement of LpX in routine laboratory practice. We present the heterogeneity of clinical and laboratory manifestations of the presence of LpX, a phenomenon which hinders LpX detection.MethodsThe study was conducted on a 26-year-old female after liver transplantation (LTx) with severely elevated total cholesterol (TC) of 38 mmol/L and increased cholestatic liver enzymes. TC, free cholesterol (FC), cholesteryl esters (CE), triglycerides, phospholipids, HDL-C, LDL-C, and apolipoproteins AI and B were measured. TC/apoB and FC:CE ratios were calculated. Lipoprotein electrophoresis was performed using a commercially available kit and laboratory-prepared agarose gel.ResultsCommercially available electrophoresis failed to demonstrate the presence of LpX. Laboratory-prepared gel clearly revealed the presence of lipoproteins with γ mobility, characteristic of LpX. The TC/apoB ratio was elevated and the CE level was reduced, confirming the presence of LpX. Regular lipoprotein apheresis was applied as the method of choice in LpX disease and a bridge to reLTx due to chronic liver insufficiency.ConclusionsThe detection of LpX is crucial as it may influence the method of treatment. As routinely available biochemical laboratory tests do not always indicate the presence of LpX, in severe hypercholesterolaemia with cholestasis, any discrepancy between electrophoresis and biochemical tests should raise suspicions of LpX disease.